Reconciling the previously incompatible through the continental scale AusAEM survey

Geoscience Australia (GA) has acquired hundreds of thousands of line kilometres of airborne electromagnetic (AEM) data over the years to better understand the Australian subsurface. A more recent planned approach of acquisition has been the AusAEM programme. This systematic effort has delivered extensive detailed conductivity-depth-models over large swaths of land. This effort will deliver a continental-scale, long lasting geophysical dataset. Simultaneously, GA's in-house processing and inversion codes enable the seamless integration of conductivity models from both helicopter and fixed wing systems, compatibility of X and Z component data from the same survey, as well as the reconciliation of historical and recent datasets. Of particular note, is the reprocessing of data using the magnitude of the measured magnetic field in the plane of the inline flight direction. It deals with many transmitter-receiver geometry problems and leads to glitch-free subsurface images. GA's efforts in advancing the modelling and inversion codes have verified the presence of geological units at deeper depths in stratigraphic sequences than we were able to resolve pre-2016. The concerted development of a strategic acquisition program together with modelling and inversion codes have allowed us to stitch together a nearly continent-wide dataset.